Water pump

ABSTRACT

A water pump for a commercial ice maker comprising a high capacity pump with a relatively large water flow rate and having an improved seal for sealing a motor shaft where it enters the pump chamber to avoid substantial leakage and resulting loss in pumping pressure.

United States Patent Barnard Dec. 26, 1972 [54] WATER PUMP [72] Inventor: Walter C. Barnard, White. Bear Lake, Minn. I

[73] Assignee: Whirlpool Corporation 22 Filed: 1:11.25, 1971 21 Appl. No.: 109,687

Related US. Application Data [63] Continuation of Ser. No. 813,536, April 4, 1969,

abandoned.

[52] US. Cl. ..415/l70 A, 415/214, 4l5/2l9 C,

, 277/174 [51] Int. Cl ..F01d 11/08, F161: 41/00, F04d'3/00 [58] Field of Search..4l5/l70 A, 196, 197, 200, 214,

[56] References Cited UNITED STATES PATENTS 2/1960 Sale at al. ..277/l74 2,684,033 7/1954 Montomery et al. ..415/170 A 2,071,736 2/1937 Farmer ..277/174 FOREIGN PATENTS OR APPLICATIONS 819,082 8/1959 Great Britain ..277/163 9/1914 Sweden ..277/174 Primary Examiner-Henry F. Raduazo Attorney-Hofgren, Wegner, Allen, Stellman & Mc- Cord 57 ABSTRACT A water pump for a commercial ice maker comprising a high capacity pump with a relatively large water flow rate and having an improved seal for sealing a motor shaft where it enters the pump chamber to avoid substantial leakage and resulting loss in pumping pressure.

2 Claims, 5 Drawing Figures PNENTEDHEBZS we saw 2 0r 2 WATER PUMP This application is a streamlined continuation of Ser. No. 813,536 filed Apr. 4, 1969, now abandoned.

Certain structure disclosed herein is also disclosed and claimed in the copending application of D. F. Swanson and W. G. Winkler Ser. No. 832,914, filed June 13, 1969 now issued as U.S. Pat. No. 3,625,023 that is assigned to the same assignee as is the present application.

One of the features of this invention is to provide an improved water pump for a commercial ice maker wherein the rate of flow of water from the pump is relatively great with resulting high pressure of the water and including an improved shaft seal adjacent the area where the motor shaft enters the pump in order to water pressure.

The invention willbe described as shown in the embodiment illustrated in the drawings. Of the drawings:

FIG. 1 is a view partially in section and partially in side elevation of a commercial ice maker including a pump embodying the invention.

FIG. 2 is a plan view of the pump housing with portions thereof shown in horizontal section.

FIG. 3 is a vertical sectional view taken substantially along line 33 of FIG. 2.

FIG. 4 is an enlarged fragmentary detail in section of the edge flange of the lower portion of the pump hous mg.

FIG. 5 is an enlarged detail sectional view of the shaft seal of the pump.

The commercial ice maker illustrated in the accompanying drawings is of the general type shown in D. F. Swanson U.S. Pat. No. 3,164,972, issued Jan. 12, 1965 and assigned to the same assignee as the present application. That is, the commercial ice maker comprises a bottom storage portion 11 for collecting the ice 12, an inclined refrigerated plate 13 on which the water is frozen to provide slabs of ice 14 which are here illustrated as formed on opposite sides of the plate 13, rather than on the one side illustrated in the above U.S. Pat. No. 3,164,972, and an electrically heated wire grid 15 in a support 16 on which the released slab of ice 17, illustrated in dotted lines in FIG. 1, drops to be subdivided into ice portions as it melts its way through the electric resistance grid 15.

The ice maker of FIG. 1 also includes a sump 18 for holding a supply of water 19, a water pump 20 in the sump 18 to receive water therefrom and force the water under pressure up a pipe 21 and a spray head 22 having a top outlet 23 and a bottom outlet 24 for spraying water onto the top and bottom surfaces of the refrigerated plate 13 for forming the ice slab 14.

The apparatus also includes refrigerant supply lines 25 and 26 for supplying liquid refrigerant to the interior of the plate 13 to produce the freezing effect and also to supply hot refrigerant to the interior of the plate 13 to melt the ice slab 14 from the plate where it slides by gravity to the position shown at 17 in dotted lines in FIG. 1 preparatory to being cut into smaller blocks or cubes.

The apparatus also includes an inclined surface conduit 27 for directing excess water that flows from the plate 13 back to the sump 18. In order to direct this water onto the surface conduit 27 there is provided a hinged deflector 28 that is pushed out of the way to the position illustrated by the dotted lines in FIG. 1 by the descent of the released ice slab 17.

The pump 20 is retained above the bottom of the sump 18 by a plurality of supporting legs 29 as is illustrated most clearly in FIG. 3. Above the pump 20 there is supported an electric motor 30 that is itself supported above the pump 20 by supporting legs 31 As shown most clearly in FIGS. 2-4, the motor 30 has a downwardly extending drive shaft 32 that extends into the pump 10. This pump includes a housing 33 that 1 has an upper part 34 and a lower part 35 that are joined together to form a coplanar chamber 36. In thechamber 36 there is positioned a usual pump impeller 37 that is mounted on the lower end of the motor shaft 32 which extends into the impeller chamber 36.

Above the impeller 37 the pump housing is formed to provide a shaft seal chamber 38 which is integral with the upper part 34 of the pump housing 33. This shaft seal. chamber 38 has an upper wall 39 through which the motor shaft 32 extends. As can be seen in FIG. 3,

the opening 40in this upper wall 39 isconsiderably larger than the diameter of the shaft 32.

Positioned within the seal chamber 38 is an annular seal retainer 41 that is held in position by an annular bead 42 on the inner surface of the chamber 38. This seal retainer 41 has a central opening 43 of larger diameter than the shaft 32 and through which this shaft extends. The retainer 41 has an inner surface 44 adjacent the impeller 37 and an outer surface 45 spaced from the seal chamber upper wall 39.

Located between this outer surface 45 of the seal retainer 41 and the upper wall 39 is an annular shaft seal 46 that has a thickness slightly less than the vertical distance between the top surface 45 and the upper wall 39. This seal 46 has a central opening defined by an annular shaft engaging surface 47 that is of an axial length (vertical width) that is considerably less than the maximum thickness of the seal 46 itself. Thus, preferably, this axial length of the surface 47 is less than one-half the maximum thickness of the seal.

The seal 46 .has a flat surface 48 facing the impeller 37 and a tapered surface 49 extending upwardly and outwardly from the shaft engaging surface 47. As can be seen in FIG. 3 this tapered surface is on the side of the seal adjacent the upper wall 39 of the chamber 38.

In a typical embodiment of the invention the shaft seal 46 has a thickness of 0.065 inch, a taper 49 of 45, a vertical spacing when at rest from its top surface to the upper wall 39 of 0.0 l 5 inch (depending on the shaft diameter this could vary between 0.010 inch and 0.020 inch), a lateral clearance between its outer periphery and the inner surface opposite this periphery of 0.09 inch and an axial length at the surface 47 of 0.01 inch.

The upper 34 and lower 35 parts of the pump housing are snapped together to form the assembled housing. In order to provide this the peripheries of these housing parts are provided with outwardly extending flanges 50 and 51. The outer rounded edge of the lower flange 50 is received in an undercut groove 52 and is received therein by being snapped past an inwardly projecting ridge 53 on an annular portion of the flange 51 which surrounds the flange 50.

In order to provide an effective seal between the two flanges 50 and 51 the flange 50 (FIG. 4) is provided with a continuous V-shaped ridge 54 on its surface that bears against the other flange 51 and the corresponding surface of this other flange 51 is provided with a 4 similarly shaped groove to receive the ridge 53.

'is a considerable saving on labor.

Because of the small shaft engaging surface 47 of the 3 seal there is very little interference with the rotation of the shaft 32; The seal also is provided with the abovementioned vertical clearance as well as lateral clearance so that it can adapt itself to the position or misalignment of the motor 30.

During the operation of the pump the water pressure within the housing 33 will of course also be applied within the seal chamber 38 and this forces the seal 46 up against the upper wall 39 to form a very tight seal not only with the shaft 32 but also with this upper wall 39.

The pump is provided with the usual water inlet opening 54 leading from the sump 18 into the impeller chamber 36 and a water outlet 55 from the chamber 36 and emptying into the previously described water outlet pipe 21. These are, of course, customary structures in a pump of this type.

Having described my invention as related to the embodiment shown in the accompanying drawings, it is my intention that the invention be not limited by any of the details of description, unless otherwise specified.

1 claim:

1. A water pump for a commercial ice maker, comprising a rigid plastic pump housing having a water inlet, a water outlet and an impeller chamber; a rotatable shaft extending into said chamber; an impeller in said chamber for rotation by said shaft to develop a water pressure in said chamber; means forming a shaft seal chamber adjacent said pump chamber integral with said housing having a radial outer wall through which said shaft extends, an annular seal retainer of rigid plastic fixed against rotation in said seal chamber having an opening of limited larger diameter than said shaft through which said shaft extends, said retainer having an inner surface adjacent said impeller and an outer surface spaced axially inwardly from said seal chamber outer wall; and a one-piece annular floating shaft seal of rigid plastic located between said retainer outer surface and said seal chamber outer wall and having a radial inner surface subjected to water pressure from said impeller and an axial opening through which said shaft extends, said shaft seal defining a frustoconical, axially outwardly widening, axially outer surface about said opening, said opening being defined by a cylindrical shaft engaging surface extending axially outwardly from said inner surface of the seal less than onehalf the axial thickness of said seal, said shaft seal having a thickness less than the distance between said retainer outer surface and said seal chamber wall and said seal chamber being defined radially outwardly by an annular surface, said shaft seal having an outer periphery spaced radially inwardly from said annular surface so as to float with respect to said seal chamber outer wall, said retainer outer surface and said annular surface of said seal chamber, and said pump housing, retainer, and seal being formed of the same plastic material.

2. The pump of claim 1 wherein said rigid shaft seal has an axial thickness less than one-half the radial thickness thereof and is tapered inwardly to said shaft engaging surface thereof. 

1. A water pump for a commercial ice maker, comprising: a rigid plastic pump housing having a water inlet, a water outlet and an impeller chamber; a rotatable shaft extending into said chamber; an impeller in said chamber for rotation by said shaft to develop a water pressure in said chamber; means forming a shaft seal chamber adjacent said pump chamber integral with said housing having a radial outer wall through which said shaft extends, an annular seal retainer of rigid plastic fixed against rotation in said seal chamber having an opening of limited larger diameter than said shaft through which said shaft extends, said retainer having an inner surface adjacent said impeller and an outer surface spaced axially inwardly from said seal chamber outer wall; and a one-piece annular floating shaft seal of rigid plastic located between said retainer outer surface and said seal chamber outer wall and having a radial inner surface subjected to water pressure from said impeller and an axial opening through which said shaft extends, said shaft seal defining a frustoconical, axially outwardly widening, axially outer surface about said opening, said opening being defined by a cylindrical shaft engaging surface extending axially outwardly from said inner surface of the seal less than one-half the axial thickness of said seal, said shaft seal having a thickness less than the distance between said retainer outer surface and said seal chamber wall and said seal chamber being defined radially outwardly by an annular surface, said shaft seal having an outer periphery spaced radially inwardly from said annular surface so as to float with respect to said seal chamber outer wall, said retainer outer surface and said annular surface of said seal chamber, and said pump housing, retainer, and seal being formed of the same plastic material.
 2. The pump of claim 1 wherein said rigid shaft seal has an axial thickness less than one-half the radial thickness thereof and is tapered inwardly to said shaft engaging surface thereof. 